Targeted eHealth intervention to reduce fear of recurrence among cancer survivors. The overall objective of this research proposal is to develop and evaluate a targeted eHealth intervention to reduce fear of cancer recurrence (FoR) among breast cancer survivors using an innovative methodological and delivery approach. Long-term cancer survivors have identified managing FoR as their most pressing unmet need. Conceptually, FoR is multi-dimensional with emotional (fear, anxiety) and cognitive (worry, preoccupation, intrusive thoughts) components. Psychosocial resources, including coping strategies and self- efficacy, are required to process FoR triggers and are a key determinant in FoR severity. Most extensively documented among breast cancer survivors, clinically significant FoR is prevalent (24-56%), lasts for years after cancer treatment, and has negative emotional and behavioral consequences. Even at low to moderate levels, FoR is positively associated with generalized anxiety, depression, symptom burden and quality of life impairments. eHealth interventions have the potential to address this salient and distressing concern through teaching coping strategies to bolster survivor's psychosocial resources, yet these novel approaches have not been explored. Aim 1 is to develop and refine FoRtitude, a targeted FoR eHealth intervention. We will build FoRtitude based on our prior work with the Northwestern University Center for Behavioral Intervention Technologies (CBITs) developing a web-based program for cancer survivors. Intervention components will include three FoR-specific coping strategy modules and telephone coaching, targeting psychosocial resources. We will pilot FoRtitude with breast cancer survivors (n=25) to collect qualitative data on intervention content and design which will be used to refine the intervention. Aim 2 is to conduct a randomized trial to evaluate the effects of four intervention components on FoR among breast cancer survivors (n=144). The Multiphase Optimization Strategy (MOST) is a novel, innovative methodological approach for building and optimizing behavioral interventions. We will use this approach to guide our research aims and design. The MOST framework allows us to evaluate our intervention components with enough statistical power to detect significant effects on FoR, our primary outcome. Five NCI-designated Community Clinical Oncology Programs (CCOPs) will serve as recruitment sites. We will also recruit from our institution, the Robert H. Lurie Comprehensive Cancer Center of Northwestern University. Using the MOST framework, results will be used to identify effective intervention components for inclusion in a large-scale confirmatory trial to be conducted through the Eastern Cooperative Oncology Group. Our findings will produce an evidence-based targeted FoR intervention that can be widely disseminated among cancer survivors at relatively low cost and in doing so, will contribute to improving quality of cancer survivorship for this growing population.